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Orthopaedic

CASE 69: right ShoulDer injury

history

A 23-year-old woman is brought to the emergency department having fallen over while on a dry ski slope. She is holding her right arm and is very reluctant to move her shoulder. She has previously had an appendicectomy and is known to have had mild attacks of asthma. She takes salbutamol and beclometasone regularly, and she is allergic to penicillin. She lives with her parents and works in the computer industry.

examination

Her shoulder shows an obvious deformity and looks ‘squared off’; the arm is held in slight abduction and is externally rotated. Both active and passive movement of the shoulder cause pain. The radial pulse and capillary refill are normal.

INVESTIGATIONS

an x-ray of the shoulder is taken, and is shown in Figure 69.1.

Figure 69.1 plain x-ray of the right shoulder.

Questions

•What is the diagnosis?

•What are the other essential examination findings that have not been commented on?

•How should this injury be managed?

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ANSWER 69

This patient has sustained an anterior dislocation of her right shoulder. Shoulder dislocations are the commonest joint dislocation, accounting for nearly half of all dislocations. The glenohumeral joint is a multi-axial ‘ball and socket’ joint and can, therefore, dislocate in any direction. However, in the majority of cases (90–98 per cent), the dislocation is anterior. Posterior dislocation is much less common and is typically secondary to either an epileptic fit or electric shock.

In order to confirm the diagnosis, radiographic assessment should be performed. The commonly used views are the AP view in combination with either an axillary or scapular view. The important point is to examine the joint with two different views. The axillary view has the advantage of showing the glenoid cavity, which may pick up any associated fracture.

An assessment of both the distal vascular and neurological function must be made in any patient with a severe limb injury. The close relationship of the shoulder joint to the brachial plexus makes a nerve injury more likely. At particular risk are the radial and axillary nerves. The incidence of axillary nerve neuropraxias following anterior shoulder dislocation is quoted at up to 10 per cent. The axillary nerve supplies sensation to the lateral aspect of the upper arm. This can be quickly assessed in a patient by testing that the patient has normal light touch sensation in the so-called ‘regimental badge area’. Medico-legally it is important to document whether this is abnormal before any attempt is made to manipulate the dislocation. Assessment of the radial nerve can be performed by testing that the patient has normal power of finger extension with the wrist dorsiflexed and the sensation is normal on the radial aspect of the dorsum of the hand.

The majority of anterior shoulder dislocations can be replaced by closed reduction. The key to successful reduction is to ensure adequate analgesia. This will relax the shoulder musculature that is typically in spasm resisting any joint movement. After successful reduction, the patient should be able to touch the contralateral shoulder tip. The shoulder should be supported in a sling, with radiological confirmation of the reduction.

KEY POINTS

•a full neurological examination must be performed prior to reduction of any dislocated joint.

•the x-ray should be carefully examined for associated fractures.

•adequate analgesia is crucial during reduction of the dislocation.

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Orthopaedic

CASE 70: FallS in the elDerly

history

A 78-year-old woman is brought to the emergency department following a fall at home. She is complaining of severe pain affecting her left leg and groin, and has been unable to get up since the fall. On further questioning, the patient has been treated with steroids for polymyalgia rheumatica for the past 12 months and had sustained an injury to the right hip 5 years ago. Her only other medication is ramipril for essential hypertension. She lives independently in a three-bedroom, two-storey house and was widowed 4 years ago. She has a supportive son who normally visits her once a week.

examination

The patient is now comfortable, having been given intravenous morphine sulphate. Her left leg appears shorter than her right one and is externally rotated. She is unable to actively lift her leg, and any attempt to passively move it results in pain. Her pedal foot pulses and sensation are intact.

Questions

•What investigation is depicted in Figure 70.1, and what does it show?

•What are the relevant factors in the history?

•What would be the further management in this patient?

•Why is the social history particularly important in this patient?

Figure 70.1 plain x-ray of the pelvis.

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ANSWER 70

This woman has sustained a (intracapsular) sub-capital neck of femur fracture. The x-ray also demonstrates a hip prosthesis on the right side, after a previous similar injury (arrow in Figure 70.2).

Figure 70.2 Fractured neck of femur on the left (anterior-posterior).

Fractured neck of the femur is a relatively common injury following a fall in the elderly population. The rate of hip fracture doubles every decade from the age of 50 years. There is a female preponderance of three to one.

This woman is at particularly high risk because of her long-term steroid use. It is now a British National Formulary (BNF) recommendation that patients on long-term steroids should have concomitant treatment for the prevention of osteoporosis.

There are two different types of fractured neck of femur, intracapsular and extracapsular. Displaced fractures that are intracapsular disrupt the intra-osseous blood supply; the remaining blood supply comes from the retinacular vessels and from the artery of the ligamentum teres. This is usually not adequate to provide enough nutrition to allow fracture healing, leading to avascular necrosis of the femoral head. In this situation, the fracture is not amenable to fixation; instead, the head and proximal femoral neck are removed and replaced by a hemi-arthroplasty. Fractures that are extracapsular do not compromise the blood supply to the femoral head, and so can be treated by fixation, i.e. a dynamic hip screw.

Irrespective of the fracture type, the initial management remains the same. It involves providing adequate analgesia, usually in the form of intravenous morphine. Intravenous fluid resuscitation is essential as these patients may well have been incapacitated for some time and will have sustained blood loss secondary to the fracture. Because these patients are likely to require an operation, they need a complete work-up for theatre. This will include blood tests (renal function, full blood count and group and save) and electrocardiogram and a chest x-ray if clinically indicated.

As part of the initial assessment, it is important to take a comprehensive history, concentrating on the mechanism of injury. It is incorrect to assume that all falls are mechanical; it is not uncommon to find that the cause of the fall is actually due to a urinary or chest infection or even a silent myocardial infarction.

The patient’s social history is also very important. This woman lives alone and has stairs to climb within her house. In order for her to be discharged, it is imperative that the discharge environment is safe. The input of physiotherapists and occupational therapists is

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essential to this assessment. If required, items such as handrails, walk-in shower, stairlifts, perching stools and toilet raises should be supplied. Similarly, other activities of daily living should be catered for, such as meals on wheels; district nurse follow-up for dressing changes; and healthcare assistants for help with shopping, cleaning and self-care.

KEY POINTS

•Femoral neck fractures are classified as either intracapsular or extracapsular.

•methods of surgical treatment depend on which type of fracture has been sustained.

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Orthopaedic

CASE 71: leFt hip pain

history

A 67-year-old woman comes to see you in the orthopaedic outpatient clinic complaining of left groin pain. The pain has been present for the past 12 months and has become progressively worse. It initially responded to ibuprofen and paracetamol, but now the pain is keeping her awake at night. Over a similar time period there has been a reduction in mobility and she now uses a stick when going outside. There has been no history of injury, and there are no neurological symptoms. She underwent a mastectomy for breast cancer 15 years ago. She takes tamoxifen and omeprazole.

examination

She is overweight with a body mass index (BMI) of 31. She walks with an antalgic gait and has a positive Trendelenberg test. There is no gross deformity of the lower limbs and the real leg lengths are equal. There is a restriction of all her left hip movements, especially internal and external rotation. Her back and knee examinations are unremarkable. Her pedal pulses are palpable, and the sensation in the leg is normal.

INVESTIGATIONS

an x-ray is taken and is shown in Figure 71.1.

Figure 71.1 plain x-ray of the pelvis.

Questions

•What does the x-ray show?

•What is a positive Trendelenberg test?

•What are the management options?

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‘good’ leg and flex the other leg at the knee. This is repeated for the ‘bad’ leg. With normal function, the pelvis is held stable by the gluteus medius acting as an abductor in the supporting leg (see Figure 71.3b). A positive result is seen when the patient has a weak or a mechanically disadvantaged gluteus medius. This results in the pelvis ‘sagging’ down on the contralateral side. In this case, when the patient stood on her left leg, the weakened gluteus medius on this side resulted in the right side of the pelvis dropping downwards (see Figure 71.3, Diagram).

A Trendelenberg gait demonstrates the same weak abductor mechanism. Normally when walking, the hip abductors are required to lift the pelvis and leg on the opposite side during the swing phase. If the abductors are not working, then the pelvis will tip downwards towards the lifted foot.

!Other frequent examination findings with osteoarthritis of the hip

•the affected leg is held adducted and in external rotation

•a positive thomas’ test: demonstrates a fixed flexion deformity

•restriction of movements of the hip joint

•normal knee and back examination

This woman’s progressive symptoms and pain at night would suggest that she would benefit from a hip replacement.

KEY POINT

•the trendelenberg test is used to determine the strength and function of the hip abductor muscles.

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